Air compression equipment for therapeutic use

ABSTRACT

Self-contained apparatus for supplying cooled, dry, clean air under pressure for therapeutic use. A motor and compressor is contained in a sound-conditioned cabinet through which air is circulated to cool the motor and compressor. Condensate from the compressed cooled air is ejected into the cooling air through a pressure relief valve.

I United States Patent 1 1 3,646,934 Foster Mar. 7, 1972 [54] AIRCOMPRESSION EQUKPMENT FOR 2,920,460 1/1960 THERAPEUTIC USE 2,920,622 /190 2,104,589 1/1938 [72] Inventor: Daniel S. Foster, Grosse Pointe, M1ch.2,190,613 2/1940 73 A W.D.Gal In Dt t,M h. 21130989 9/1938 Ss'gnee e2,770,107 11/1956 Burgess ..62/292 x [22] Filed: Nov. 20, 1969 PrimaryExandner-Richard A. Gaudet [2]] App! 878363 Assistant Examiner-G. F.Dunne Attorney-Whittemore, Hulbert & Belknap [52] US. CL ....lZ8/2l2,62/296, 165/123 [51] Int. Cl. J, ..A6lm 16/02 [57] ABSTRACT [58]FieldofSearch ..l28/2l2, 191 R, 191 A, l B,

128/194 204, I85; 62/296 401; 165/120 121 Self-contamed apparatus forsupp ymg cooled, dry, clean arr 122 under pressure for therapeuhc use. Amotor and compressor 1s contained in a sound-conditioned cabinet throughwhich air is circulated to cool the motor and compressor. Condensate[56] References cued from the compressed cooled air is ejected into thecooling air UNITED STATES PATENTS through a pressure relief valve.

PAIENIEBHAR 1 m2 SHEET 1 OF 2 Wu F ma TE NT M W 8 mm 00 4 I C C R E S TE S E m RM P M 0 c 2 4 4 4 ATTOR EYS PATENTEUMAR 11912 SHEET 2 0F 2 IINVENTOR. DAN L S FOSTER BRIEF SUMMARY OF THE INVENTION The presentinvention is intended for use in hospitals for supplying air undercontrolled premure for therapeutic use. It is essential that this air bedry, bacteria free, and also free of oil vapors and the like.Preferably, the unit is portable and comprises a wheeled cabinet whichmay be moved from room to room.

A further requirement of the system is that it be very quiet inoperation, producingin general no more noise than an efficientrefrigerating unit.

The quietness is accomplished by mounting the air compressor and anelectric motor for driving the compressor in a sound-conditioned chamberin the cabinet. Since this chamber is a sound-conditioned chamber,dissipationof the heat generated by the motor and compressor is aproblem. This problem is taken care of by providing an additional motorin the chamber and a fan or blower for circulating cooling air throughthe chamber. This fan or blower is illustrated herein as mounted on thetop of the chamber which contains the motors and the air compressor.Alternatively, it may be mounted within the chamber.

The equipment is intended for providing dry, compressed air for deliverydirectly to a patient for breathing at a controlled pressure. Thepressure is regulated by a pressure regulating relief valve which isdesigned to open whenever the patient exhales and to close as thepatient inhales.

The compressor delivers the air at an elevated temperature as forexample 200 F., and in order to cool the air for delivery to a patientit passes through a coiled heat exchange tube, preferably finned, whichbrings the air to approximately room temperature. This cooling of theair condenses moisture from it so that the air delivered to the patientunder controlled pressure is essentially dry.

The fan or blower circulates air around the motor and compressor chamberand in addition, circulates air through the chamber where it cools themotor and compressor, and more particularly, provides the cooling actionwhich reduces the temperature of the compressed air as it passes throughthe heat exchange tube.

The pressure relief valve which controls the pressure of the airdelivered to the patient is arranged in conjunction with a receptaclefor the condensate so that the air which escapes through the pressurerelief valve carries with it the condensate and delivers it into the airflowing through the chamber.

The air intake to the compressor includes an air intake tube extendingto the exterior of the cabinet where it is provided with a filter unithaving provision for ready replacement of filters designed to removeairborne bacteria.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of theequipment.

FIG. 2 is a side elevational view with parts broken away. FIG. 3 is avertical sectional view on the line 3-3, FIG. 2. FIG. 4 is adiagrammatic view showing the airflow.

DETAILED DESCRIPTION The air compression equipment is intended for readymobility as between rooms of a hospital, and is accordingly providedwith wheels 10 and a handle 11, supporting posts 12 being providedadjacent the front of the unit.

As best seen in FIG. 1, the unit comprises a cabinet 14 whichconveniently may be made of sheet metal. The cabinet is generallyrectangular but adjacent its top rear portion there is an upwardlyextending enlargement 16 designed to contain certain equipment.

Referring next to FIG. 4 there is illustrated the fiow of air throughthe cabinet to a delivery structure including a filter. The intake ofroom air is through a fitting indicated generally at 18 convenientlylocated in the top surface 20 of the cabinet and including an upwardlyextending tubular portion 22 having an upwardly facing seat 24 on whichis mounted t a foraminous support structure 26. The portion 22 isprovided with a plurality of outwardly extending pins 28 which engage ininclined slots formed at the interior surface of a ring 30 carrying aninner ring 32 which is connected thereto by a flexiblesnapring 34. Thearrangement provides for removal of the rings30 and-32 upon a partialrotation thereof, andremoval and replacement of a filter element-36. Thefilter is intended to remove airborne bacteria and mayfor example be a10- micron filter. The compressor 40 draws air through the filter 36from which it passes along a conduit 42 to a transparent receptacle 44.From the compressor 40 the compressed air, which may at this time have atemperature of approximately 200 due to compression, passes to a coolingcoil 46 and thence to a combined pressure regulating discharge valve andcondensate collector indicated at 48. Finally, the conduit 42 leads to afinal filter unit 50 mounted on the exterior of the cabinet whichprovides a connection 52 for -a conduit to lead the compressed air tothe point of use. A pressure meter'54 is provided which is connected tothe conduit 42 to give a direct reading of the pressure at which the airis supplied;

Referring now particularly to FIGS. 2 and 3 the sidewalls 56 of thecabinet are provided at their inner surfaces with soundinsulatingmaterial 58. Within the cabinet is a separate soundinsulated chamber 60having sidewalls 62 provided at their interior surfaces withsound-insulating material 63. The walls 62 are spaced from the cabinetsidewalls 56 and provide spaces 64 and 66 therebetween for flow of airinto and out of the chamber 60. The bottom wall 68 of the cabinetconstitutes the bottom wall of the chamber and is therein provided withsound-insulating material 70.

The compressor 40 is driven by an electric motor 72. The compressor 40and motor 72 are located within the sound-insulated chamber 60. Theupper portion of the chamber 60 is closed by a top plate 74 so that themotor and compressor are completely enclosed within a sound-insulatingchamber the front and rear walls of which are not illustrated but whichare also provided with sound-insulating material similar to thatillustrated at 58, 63 and 70.

While the chamber 60 is thus efiiciently sound-conditioned, this in turncreates a problem as a result of heating of the chamber due to theoperation of the compressor 40 and the motor 72. In order to overcomedifficulties occasioned by excessive heat within the chamber 60, acirculation of cooling air is provided through the chamber. For thispurpose, adjacent the top rear of the cabinet there is provided alouvered construction indicated at 76. Mounted on the top plate 74 ofthe chamber is a blower 78 which has an outlet port 80 through which theair is blown downwardly through the passage 64 and into the chamber 60through elongated ports 82. The flow of air through the chamber isthence upwardly around the motor and compressor and outwardly throughsimilar elongated ports 84 adjacent the top of the chamber 60. This air,which has cooled the motor and compressor, then moves downwardly and isdischarged through ports 86 located in the bottom of the cabinet.

The blower 78, which as previously described is located on the plate 74which forms the top closure of the chamber 60, is powered by a motor 88which is located within the chamber 60.

The cooling coil 46 is preferably in the form of a finned tube which maybe of substantial length such for example as 36 inches, and which may befonned into sinuously curved multiple convolutions. v

The pressure relief and condensate discharge unit 48 comprises adownwardly movable pressure relief valve having a stem 90 extendingthrough an opening in a cup 92 having a discharge orifice 94. Within thecup 92 is a compression spring urging the valve upwardly against itsseat, with compression of the spring being adjustable by threadedadjustment of the cup 92 on structure 96 which includes the valve seat.The air as it passes through the heat exchange or cooling structure 46is cooled and condensate collects as a result of the cooling. Thecondensate enters the assembly 48 above the pressure relief valve andwhenever the pressure relief valve opens, the condensate is blowndownwardly through the valve port and out the discharge orifice 94.

In operation the pressure relieve valve is set to operate at apredetermined value, for example, 50 p.s.i., such that the air suppliedthrough the external filter fitting S to the patient falls below the setpressure during inhalation by the patient. When the patient exhalespressure of the air within the system builds up to the relief pressureset at the relief valve assembly 48 so that the valve opens anddischarges air to maintain the air pressure at the set value.Accordingly, in normal operation the presure regulating valve 50 openseach time the patient exhales and accordingly, there will be noopportunity for a substantial accumulation of condensed liquid in theunit 48.

The relatively small amount of liquid which is thus discharged throughthe orifice 94 upon each exhalation by the patient, is preferablyvaporized as it passes through the valve and is readily evaporated bythe air passing through the chamber 60. This operation is rendered moreeffective due to the fact that the air circulating through the chamberis substantially heated by the absorption of heat from the motors 72 and88 as well as the compressor 40.

' It will be noted that the pressure relieve valve unit 48 is alsolocated within the sound-insulated chamber 60 so that the slight soundoccasioned by periodic opening and closing of the valve and the escapeof air under pressure is efficiently silenced.

A switch 98 controlling the compressor motor 72 and the blower motor 88is preferably provided on the inclined panel surface 99 of the cabinetfor ready access.

The foregoing construction, the details of which have been described, ischaracterized particularly in the effective silencing of the operationby inclusion of the compressor and the two motors within thesound-insulated chamber together with a circulation of air through thecabinet which causes the air entering the louvered wall 76 of thecabinet to pass over the finned heat exchange structure 46 and thencethrough the chamber 60. The arrangement for frequent and regulardischarge of accumulated moisture from the system through the pressurerelief valve is also an important feature, the moisture thus dischargedbeing carried out of the chamber 60 by the cooling air circulatingtherethrough. Finally, an important advantage of the definedconstruction is the provision of the readily removable and replaceablefilter structure which is effective to prevent entry of airbornebacteria into the system.

What I claim as my invention is:

1. Apparatus for supplying cooled air under controlled pressureconditions for therapeutic use to a patient enclosure comprising acabinet, a sound-conditioned chamber within said cabinet, an aircompressor and compressor motor for driving said compressor and apressure regulating valve in said chamber, an air cooling tube in saidcabinet exterior of said chamber, conduit means connecting said coolingtube between said compressor and valve, and said valve to said patientenclosure, said pressure relief valve operating in response to thepressure in said conduit connecting said pressure relief valve to saidpatient enclosure, and means for circulating cooling air across saidcooling tube and thence through said chamber.

2. Apparatus as defined in claim 1 in which the means for circulatingair through said chamber comprises a blower within said cabinet exteriorof said chamber, and a blower motor connected to said blower and locatedin said soundconditioned chamber.

3. Apparatus as defined in claim 2 in which said chamber occupies thelower part of said cabinet leaving a compartment above said chamberwithin said cabinet, said blower being mounted on the top of saidchamber and connected to said blower motor through the top wall of saidchamber.

4. Apparatus as defined in claim 3 in which one outer wall of saidcabinet has louvers therein communicating with said com fartment, thesidewalls of said chamber being s aced inwar ly from the sidewalls ofsaid cabinet and e ming air passages therebetween, a port connectingsaid compartment with one of said passages, ports connecting saidchamber with both of said passages, and an outlet port connecting saidother passage to atmosphere.

5. Apparatus as defined in claim 1, said pressure relief valve includinga valve seat and movable valve member in position to collect moisturecondensed as a result of cooling compressed air in said cooling tube,opening of said valve serving to discharge condensate from thecompressed air system through said valve.

6. Apparatus as defined in claim 5 in which said pressure relief valveis located in a branch passage extending downwardly from a horizontallyextending portion of said conduit connecting said air cooling tube andpatient enclosure.

7. Apparatus for supplying air under controlled pressure conditions fortherapeutic use comprising a cabinet, a soundconditioned chamber withinsaid cabinet, an air compressor and compressor motor for driving saidcompressor in said chamber, means for circulating cooling air throughsaid chamber comprising a blower within said cabinet, a blower motorconnected to said blower and located in said soundconditioned chamber,heat exchange tubing connected to said compressor and located in saidcabinet in the path of airflow induced by said blower, said chambercomprising the lower part of said cabinet leaving a compartment abovesaid chamber within said cabinet, said blower being mounted on the topof said chamber and connected to said blower motor through the top wallof said chamber, said chamber have sound-insulated sidewalls spacedinwardly from the sidewalls of said cabinet to define lateral airpassages therebetween, said blower communicating with one of saidpassages, an air inlet from the bottom of said one passage to saidchamber, an outlet from said chamber to the top of said other passage,said other passage having a discharge opening at its bottom.

"H026 nno

1. Apparatus for supplying cooled air under controlled pressureconditions for therapeutic use to a patient enclosure comprising acabinet, a sound-conditioned chamber within said cabinet, an aircompressor anD compressor motor for driving said compressor and apressure regulating valve in said chamber, an air cooling tube in saidcabinet exterior of said chamber, conduit means connecting said coolingtube between said compressor and valve, and said valve to said patientenclosure, said pressure relief valve operating in response to thepressure in said conduit connecting said pressure relief valve to saidpatient enclosure, and means for circulating cooling air across saidcooling tube and thence through said chamber.
 2. Apparatus as defined inclaim 1 in which the means for circulating air through said chambercomprises a blower within said cabinet exterior of said chamber, and ablower motor connected to said blower and located in saidsound-conditioned chamber.
 3. Apparatus as defined in claim 2 in whichsaid chamber occupies the lower part of said cabinet leaving acompartment above said chamber within said cabinet, said blower beingmounted on the top of said chamber and connected to said blower motorthrough the top wall of said chamber.
 4. Apparatus as defined in claim 3in which one outer wall of said cabinet has louvers thereincommunicating with said compartment, the sidewalls of said chamber beingspaced inwardly from the sidewalls of said cabinet and defining airpassages therebetween, a port connecting said compartment with one ofsaid passages, ports connecting said chamber with both of said passages,and an outlet port connecting said other passage to atmosphere. 5.Apparatus as defined in claim 1, said pressure relief valve including avalve seat and movable valve member in position to collect moisturecondensed as a result of cooling compressed air in said cooling tube,opening of said valve serving to discharge condensate from thecompressed air system through said valve.
 6. Apparatus as defined inclaim 5 in which said pressure relief valve is located in a branchpassage extending downwardly from a horizontally extending portion ofsaid conduit connecting said air cooling tube and patient enclosure. 7.Apparatus for supplying air under controlled pressure conditions fortherapeutic use comprising a cabinet, a sound-conditioned chamber withinsaid cabinet, an air compressor and compressor motor for driving saidcompressor in said chamber, means for circulating cooling air throughsaid chamber comprising a blower within said cabinet, a blower motorconnected to said blower and located in said sound-conditioned chamber,heat exchange tubing connected to said compressor and located in saidcabinet in the path of airflow induced by said blower, said chambercomprising the lower part of said cabinet leaving a compartment abovesaid chamber within said cabinet, said blower being mounted on the topof said chamber and connected to said blower motor through the top wallof said chamber, said chamber have sound-insulated sidewalls spacedinwardly from the sidewalls of said cabinet to define lateral airpassages therebetween, said blower communicating with one of saidpassages, an air inlet from the bottom of said one passage to saidchamber, an outlet from said chamber to the top of said other passage,said other passage having a discharge opening at its bottom.